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Subject: Re: [Qemu-devel] [RFC 0/2] GET_EMULATED_CPUID support with
	"allow-emulation" option
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To: Eduardo Habkost <ehabkost@redhat.com>
Cc: Michael Mueller <mimu@linux.vnet.ibm.com>, kvm@vger.kernel.org, "Michael S. Tsirkin" <mst@redhat.com>, Alexander Graf <agraf@suse.de>, qemu-devel@nongnu.org, Christian Borntraeger <borntraeger@de.ibm.com>, "Gabriel L. Somlo" <gsomlo@gmail.com>, Borislav Petkov <bp@alien8.de>, "Jason J. Herne" <jjherne@linux.vnet.ibm.com>, =?ISO-8859-1?Q?Andreas_?= =?ISO-8859-1?Q?F=E4rber?= <afaerber@suse.de>

Il 05/06/2014 19:19, Eduardo Habkost ha scritto:
> On Thu, Jun 05, 2014 at 06:57:57PM +0200, Paolo Bonzini wrote:
>> Il 05/06/2014 18:54, Alexander Graf ha scritto:
>>>>
>>>> What about:
>>>>
>>>> - letting "-cpu foo,+emulatedfeature" just work
>>>>
>>>> - adding emulated=yes that blindly enables all emulated features
>>>>
>>>> - making "-cpu ...,check" prints a warning for emulated features
>>>> unless emulated=yes
>>>
>>> How about we remove the emulated=yes from this list? Then I'm happy :).
>>
>> So:
>>
>> - "-cpu foo" doesn't enable any emulated feature
>
> What if "foo" already has movbe in the CPU model definition?

It will be disabled.

>>
>> - "-cpu foo,+movbe" does
>
> What if I want movbe enabled if and only if it is _not_ emulated?

Pick a CPU model that has it.

> The whole point here is to never ever ever enable an emulated feature
> unless it was explicitly what the user wanted.

"+foo" could be enough.

> "nice and descriptive message" needs to be better specified. Messages on
> stderr are useless for management software.

I'm not sure this feature is for management software users.

Paolo